Acute Epiglottitis

Introduction

Acute epiglottitis (also called acute supraglottitis when inflammation involves epiglottis plus other supraglottic structures) is a potentially life-threatening infection causing inflammation and swelling of the epiglottis, which can lead to sudden upper airway obstruction. While classically a disease of children, its epidemiology has shifted over recent decades, and adult cases are increasingly recognized.

Early recognition and prompt management are critical, because without appropriate treatment, the swelling may progress rapidly, possibly resulting in respiratory failure. Key challenges in management include diagnosis (differentiating from other causes of sore throat, stridor, or upper airway obstruction), and securing the airway safely in the setting of inflammation.

Anatomy and Pathophysiology

Anatomy of the Epiglottis

The epiglottis is a leaf-shaped cartilage (elastic cartilage) situated at the entrance of the larynx, posterior to the root of the tongue and in front of the laryngeal inlet.
Its role is largely to protect the lower airways during swallowing: it folds down to help direct food/liquids away from the trachea.
It is covered by a mucous membrane and has a rich vascular supply and lymphatic drainage.

Pathophysiology of Acute Epiglottitis

In acute epiglottitis, there is sudden inflammation (often infectious) of the epiglottis and possibly surrounding supraglottic tissues (aryepiglottic folds, false vocal cords).
The mucosal edema leads to swelling, and since the epiglottis sits over the airway, this swelling can obstruct airflow.
The obstruction can be partial or progress to complete, rapidly compromising ventilation.
In severe cases, inflammation may spread, or abscesses may form, exacerbating obstruction.

Causative Agents

Historically, Haemophilus influenzae type b (Hib) was a leading cause in children. However:

After introduction of Hib vaccination programs, the incidence of Hib-associated epiglottitis in children has dramatically decreased.
Other bacteria have become more prominent: Streptococcus pneumoniae, Streptococcus pyogenes, Staphylococcus aureus, Neisseria meningitidis, and others.
Viruses can also be involved (less commonly), or the condition can be secondary to trauma, thermal injury, caustic agents, foreign body ingestion, or allergic reactions.
Recently, there have been case reports of acute epiglottitis associated with COVID-19 infection.

Predisposing Factors

Age: Children (especially pre-vaccination era) are high risk; now adult incidence is rising.
Immunocompromise: Diabetes, HIV, other systemic illness.
Comorbidity: Chronic lung disease, obesity etc.
Delayed vaccination or lack of vaccination (for Hib).
Trauma or burn injury to the airway.
Foreign body ingestion or irritation.
Allergic predisposition in some cases.

Epidemiology

In the pre-vaccination era, acute epiglottitis was more common in children (especially under age 5).
Post-Hib vaccine, pediatric cases have dropped significantly; adult cases now represent a larger share of patients.
Adult cases tend to occur in middle age; studies report mean age around 40-50 years in many adult case series.
Male to female ratio in adults is often more males than females, but this can vary.
Incidence depends on vaccination coverage, public health systems, awareness, and access to healthcare.

Clinical Presentation

The presentation can vary by age and severity, but there are some classic features.

Onset

Rapid onset over hours in many cases; sometimes after a prodrome of sore throat.
Progression can be fast once swelling begins; airway compromise can happen quickly.

Symptoms

Sore throat: Often severe, out of proportion to oropharyngeal findings.
Odynophagia (pain on swallowing), dysphagia.
Muffled (“hot potato”) voice, or changes in voice quality.
Drooling: inability to swallow saliva due to pain or obstruction.
Stridor: inspiratory stridor is a key sign of upper airway obstruction.
Dyspnea and increased work of breathing; patients may sit leaning forward to ease breathing.
Fever, malaise.
Neck swelling or tenderness in some cases.
Less classic presentation in adults may lead to delay in diagnosis: mild sore throat, no drooling, minimal change in throat appearance.

Signs on Physical Examination

Patient often in tripod position: sitting upright, leaning forward, neck extended.
Stridor: inspiratory (or biphasic) depending on obstruction level.
Tachypnea, use of accessory respiratory muscles, intercostal retractions (in children).
Increased work of breathing; may have cyanosis if severe.
Muffled or hoarse voice.
Oropharyngeal exam may show relatively little, sometimes no dramatic pharyngeal swelling, even though epiglottis is severely inflamed. This is particularly true in adults.

Laboratory Findings

Elevated inflammatory markers: white blood cell count (especially neutrophils), C-reactive protein.
Blood cultures may help identify systemic spread. Some adult cases had positive blood cultures for Haemophilus influenzae type b.
Imaging (less laboratory) plays a role in diagnosis; see below.

Diagnosis

Prompt diagnosis is vital. Often diagnosis is clinical, supported by imaging and/or laryngoscopy.

Differential Diagnosis

Because many other conditions can cause sore throat, dysphagia, stridor, etc., acute epiglottitis must be differentiated from:

Peritonsillar abscess
Retropharyngeal abscess
Tonsillitis, pharyngitis, or uvulitis
Foreign body in airway or food impaction
Allergic airway edema (e.g. angioedema)
Laryngitis or croup (in children)
Trauma or burn injury

Clinical Evaluation

History: onset, speed of worsening symptoms, voice change, drooling, position of comfort, comorbidities (e.g., immunosuppression).
Physical exam: assessment of upper airway patency, stridor, ability to swallow saliva, respiratory distress, cyanosis. But careful not to provoke further airway compromise with manipulations in severe cases.

Imaging

Lateral neck X-ray ("soft tissue neck lateral view") often shows the “thumbprint sign” — swollen epiglottis projecting into the airway lumen. This is a classic sign.
Views showing thickened aryepiglottic folds and narrowed airway.
In unstable patients or where radiography could delay care (or risk provoking airway compromise), imaging may be deferred.

Endoscopic / Laryngoscopic Examination

Flexible fiberoptic laryngoscopy or direct laryngoscopy to visualize the epiglottis.
Inspection will show a red, swollen epiglottis; may see edema of supraglottic structures.
Performed only by experienced personnel, in settings where airway intervention can be done immediately if needed.

Laboratory and Microbiology

Blood cultures.
Throat swabs (though superficial swabs may not capture epiglottic pathogens).
Possibly epiglottic swab or aspirate if safe and possible.
Laboratory tests: complete blood count, inflammatory markers, possibly arterial blood gas if respiratory compromise is suspected.

Severity Assessment

Important factors associated with needing airway intervention:

Presence of stridor strongly correlated with need for airway intervention.
Sitting upright (patient leaning forward) suggests airway distress.
Oxygen saturation fall, use of accessory muscles, increased respiratory rate.
Comorbidities such as diabetes, immunosuppression.
Radiographic severity: how much swelling and airway narrowing.

Management

Management is a medical emergency. Goals are to secure the airway, treat the infection/inflammation, support the patient systemically, and prevent complications.

Initial Stabilization

Call for help: ENT (otolaryngology), anesthesia, ICU as needed.
Make the patient comfortable; minimize agitation which could worsen airway obstruction.
Keep patient upright; avoid supine position in severe cases.
Ensure high-flow oxygen; monitor vital signs, oxygen saturation, respiratory rate.
Establish intravenous access.

Airway Management

This is the crux of management because airway compromise can be sudden.

Intubation (endotracheal) when necessary — in controlled setting, with experienced personnel.
- Preferably under sedation with minimal manipulation; sometimes inhalational induction in children where IV access is difficult.
- Smaller tube may be needed, as swelling can make navigation difficult.
Tracheotomy or cricothyrotomy may be required if intubation fails or is unsafe. Some protocols suggest having surgical backup readily available.
Timing: in settings of clear airway distress, stridor, drooling, or rapidly worsening symptoms, early intervention is preferable rather than "wait and see". Delaying can result in emergency airway situations, which have higher risk. Studies have shown that in children, some patients under observation group later required emergency tracheotomy under less favorable conditions.

Antimicrobial Therapy

Empiric broad-spectrum intravenous antibiotics targeting common pathogens (both anaerobes and aerobes). Examples include third-generation cephalosporins, plus agents active against Strep, Staph, and Gram-negatives.
Once culture results available, narrow therapy appropriately.

Adjunctive Therapy

Corticosteroids: often given to reduce inflammation and edema; whether they improve outcomes definitively is less clearly proven, but many clinical protocols include steroids.
Nebulized epinephrine (in some cases) to reduce mucosal swelling (especially in children).
Humidified oxygen and nebulized medications to soothe mucosa.

Supportive Care

Intravenous fluids, antipyretics, analgesics.
Monitoring in ICU or semi-ICU for more severe cases.
Frequent reassessment of airway status.

Complications

Complete airway obstruction leading to respiratory arrest.
Hypoxia, which may lead to secondary organ damage.
Spread of infection: epiglottic abscess, extension to deep neck spaces (parapharyngeal, retropharyngeal), even mediastinum in rare cases.
Sepsis.
If intubated: complications like accidental extubation, tube blockage, ventilator-associated pneumonia.
Prolonged hospitalization, possibly ICU stay.

Prognosis

With prompt diagnosis and appropriate management, prognosis is generally good; most patients recover fully. Studies in adults show low mortality when airway is properly supported.
However, morbidity and mortality increase in:
- Delayed diagnosis
- Older age
- Presence of comorbidities (e.g. diabetes)
- Severe airway compromise at presentation
- Inadequate airway management
In children prior to vaccination, mortality was higher. Now mortality is much lower, but the risk remains in settings with delays or less access to advanced care.

Prevention

Vaccination is key: Hib vaccine has dramatically reduced incidence of Hib-related epiglottitis in children.
Good public health measures: awareness, prompt treatment of throat infections.
Early recognition and care seeking when symptoms like severe sore throat, drooling, and swallowing difficulty appear.
For health-care workers: training in airway emergencies, preparedness to secure airway rapidly.

Emerging Issues and Recent Trends

Shifts in microbiology: with decline of Hib, other pathogens are becoming more important.
Adult epiglottitis increasing in relative frequency, perhaps due to decreased Hib in children, aging population, or better recognition.
COVID-19‐associated epiglottitis: case reports and small series suggest SARS-CoV-2 infection can present with epiglottitis or supraglottitis. Higher risk of airway intervention in some of these cases.
Delayed presentations or atypical features in adults: less drooling, less dramatic oropharyngeal findings, which may lead to misdiagnosis or delay.
Resource limitations: in low-resource settings, securing airway and monitoring may be more challenging; thus outcomes can be worse.

Case Studies & Key Evidence

Selected findings from large series/studies:

In 129 adult cases from Northern California: mean age ~47 years; male:female ~1.8:1; sore throat (~95%) and odynophagia (~94%) were almost universal. Only ~15% required airway intervention (intubation or tracheotomy). Factors most strongly associated with airway intervention were presence of stridor and sitting upright.
In a review of 55 pediatric cases, some patients under observation required tracheotomy; some had respiratory arrest when airway was assumed to remain patent prematurely. This study led to suggestions that once diagnosis is made, preparations for airway control and possibly even elective tracheotomy should be considered.
In some reports, diabetes mellitus was shown to worsen outcomes or be associated with more severe disease.

Practical Protocol for Care

Below is an outline of a practical protocol that can be used in hospitals/emergency settings. Adapt to local resources.

Step	Action
Recognition and Triage	Immediately recognize red-flag symptoms (drooling, stridor, severe sore throat, difficulty swallowing saliva). Triage to urgent/critical care.
Preparation	Alert ENT, anesthesiology, ICU. Prepare for possible airway intervention (equipment, personnel).
Assessment	History, physical exam; vital signs, oxygen saturation. Try to avoid maneuvers that may provoke airway closure.
Supportive Measures	Give oxygen, IV fluids, start monitoring. Keep patient calm, upright.
Diagnostic workup	Lateral neck X-ray if safe and available; labs; blood cultures; if possible, laryngoscopy in controlled environment.
Airway Plan	If signs of airway compromise: plan for secure airway (intubation or surgical airway). Decide location (OR, ICU) and personnel. Ensure backup plan.
Antibiotics and Adjuncts	Start empiric IV antibiotics. Add steroids. Consider nebulized epinephrine in children if needed.
Ongoing Care	ICU / high dependency monitoring. Serial examinations of airway. Plan for extubation when swelling has subsided and patient is stable. Care for complications.
Discharge Planning	Once patient is stable, swallowing and airway function normal. Educate patient/family. Ensure follow-up.

Special Considerations: Children vs Adults

Feature	Children	Adults
Frequency	Historically more common, especially before Hib vaccine	Less common historically but rising proportionally
Presentation	Often rapid, dramatic; drooling, stridor, high fever; may deteriorate rapidly	Presentations may be less obvious; sore throat out of proportion; drooling not always present; sometimes milder early
Airway risk	Higher risk of rapid airway compromise due to smaller airway diameter	Still risk, especially with comorbidities; but airway often more stable until later stage
Management setting	Often in pediatric ICU; need for experienced anesthetists familiar with pediatric airway	Often in adult ICU; similar need for experienced personnel
Mortality	Lower now with vaccination, but historically higher	Mortality low if care prompt, but risk in older patients or those with comorbidities or delays

Complication Management & What to Watch For

Signs of worsening airway obstruction: increasing stridor, use of accessory muscles, declining oxygen saturation, drooling, inability to swallow saliva.
Silent chest or loss of stridor can paradoxically signal complete obstruction — very dangerous.
Tube blockage or accidental extubation if intubated; strict monitoring, suctioning, tube care required.
Abscess formation or spread may require surgical drainage.
Sepsis: treat aggressively.
Post-extubation assessment: ensure airway swelling has resolved enough; do laryngoscopy if needed.

Prognosis and Outcomes

As stated, with good care, most patients recover without long-term sequelae.
Outcome depends heavily on how early the diagnosis is made and how quickly the airway is secured if needed.
Mortality is rare but can occur, especially in settings with resource constraints, delays, or severe presentation.
Length of hospital stay varies; in milder adult cases, may be a few days; in severe cases or in children with prolonged intubation, may be longer.

Summary

Acute epiglottitis is a medical emergency characterized by inflammation of the epiglottis. Early recognition is vital because the airway can become obstructed rapidly. Although historically more common in children, its epidemiology has changed: Hib vaccination has reduced pediatric cases; adult presentations are proportionally increasing. Key features include severe sore throat, difficulty swallowing, drooling, stridor, and voice changes. Diagnosis involves clinical suspicion, imaging such as the lateral neck view, and laryngoscopic examination when safe. Management centers on securing the airway, administering antibiotics, and using adjunctive therapies like steroids. With prompt, appropriate care, prognosis is good; delays or inadequate management lead to higher morbidity and mortality. Prevention via vaccination, awareness, and timely healthcare are important.

Acute Epiglottis